WASHINGTON — The brinkmanship of Afghan President Hamid Karzai threatens to derail a long-term security relationship with the United States, even though such a commitment is in both countries’ interests, analysts say.

“Karzai is forcing us toward a zero option, which would be tragedy for the Afghan people,” said Marc Chretien, a former political adviser to the coalition command in Afghanistan, referring to an option to remove all American forces by the end of next year.

Without an agreement, Afghanistan would lose military support and international financial commitments.

“If President Karzai has set his country down the path of going on its own, he will have succeeded in tying the hands of his successor in terms of having Afghanistan enjoy a future,” Chretien said. Karzai is term-limited and cannot stand for elections scheduled for April.

At issue is the so-called bilateral security agreement that would create a legal framework for American troops to remain after 2014, when the combat mission ends.

The Pentagon has said those troops would be designated to assist Afghanistan’s young military and provide counterterrorism forces to target al-Qaida militants or their affiliates. The size of the U.S. force has not been determined.

The latest obstacle came during a visit by President Obama’s national security adviser, Susan Rice, who met with Karzai on Monday in Kabul and urged him to sign the agreement.

Karzai said he would sign it, but he didn’t say when and made new demands, including that the United States release Afghans being held at Guantanamo Bay.

Washington would like the agreement to be signed soon to provide Afghans with some certainty about their future and allow the United States to prepare for a follow-on force, State Department spokeswoman Jen Psaki said.

Defense Secretary Chuck Hagel told USA Today on Monday that the United States wasn’t imposing deadlines on Karzai, but a deal by year’s end was required to give the United States and its allies time to plan the post-2014 force.

Karzai made his latest demands shortly after a grand council, which he had convened, urged the president to sign the security agreement.

The issues Karzai has raised are not new and have been hashed out in previous years, said Michael O’Hanlon, an analyst at the Brookings Institution. “We’ve seen this movie before,” he said.

The White House has said that unless the agreement is signed quickly, the United States will have no choice but to begin planning to remove all U.S. forces by the end of 2014.

That decision would jeopardize billions of dollars in international aid that has been pledged to Afghanistan, the White House said.

Karzai may believe that the delays will provide him with leverage over the United States when Washington presses him on issues such as combating corruption, holding clean elections and other issues, O’Hanlon said.

In reality, Karzai may be overplaying his hand, analysts say. Karzai is misjudging American politics, pointing out that the majority of Americans would prefer that U.S. troops not remain in Afghanistan, Chretien said.

“He persists in extracting more concessions from us with the thought that we would do anything to continue our assistance to Afghanistan,” Chretien said. “This is not realistic.”